As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD - FLT 4007 - RUDDER SYSTEMS 1 AND 2 INOPERATIVE. EMERGENCY DECLARED. MECHANICAL REVERSION MODE CONFIRMED. FIRST OFFICER FELT THAT HYDRAULIC SYSTEM WAS LOST. AUTOPILOT AND YAW DAMPENER FAILED. REMOVED AND REPLACED RUDDER POWER CONTROL UNIT. OPERATIONAL CHECK GOOD. (X)